The present invention is related to the field of solid-state light beam tunable devices, referred to herein as light modulators.
U.S. Pat. No. 7,002,697 B2 discloses an optical instrument which includes a thermo-optically tunable, thin film, free-space interference filter having a tunable passband which functions as a wavelength selector. The filter includes a sequence of alternating layers of amorphous silicon and a dielectric material deposited one on top of the other and forming a Fabry-Perot cavity structure having: a first multi-layer thin film interference structure forming a first mirror; a thin-film spacer layer of amorphous silicon deposited on top of the first multi-layer interference structure; and a second multi-layer thin film interference structure deposited on top of the thin-film spacer layer and forming a second mirror. The filter further includes a lens for coupling an optical beam into the filter; an optical detector for receiving the optical beam after the optical beam has interacted with the interference filter; and circuitry for heating the thermo-optically tunable interference filter to control a location of the passband.
U.S. Pat. No. 7,049,004 B2 discloses a dynamically tunable thin film interference coating including one or more layers with thermo-optically tunable refractive index. Tunable layers within thin film interference coatings enable a new family of thin film active devices for the filtering, control, and modulation of light. Active thin film structures can be used directly or integrated into a variety of photonic subsystems to make tunable lasers, tunable add-drop filters for fiber optic telecommunications, tunable polarizers, tunable dispersion compensation filters, and many other devices.